Portable electronic devices, such as portable terminals, tablet computers, smartphones, etc., may use rechargeable batteries as power supply units in order to provide a mobility thereof. Accordingly, users of the portable electronic devices can more conveniently use the electronic devices beyond a wired environment for power supply to the electronic devices.
When the residual quantities of the batteries are insufficient, the portable electronic devices may recharge the batteries using external power supply devices. For example, the users of the portable electronic devices may recharge the batteries of the portable electronic devices by using auxiliary battery (power bank) devices.